Mitigation of Seismic Risk in Older Concrete Buildings NEES-R Grand Challenge Thalia Anagnos, Mary Comerio, Tara Hutchinson, Ricky Lopez, Adolfo Matamoros, Peter May, Jack Moehle (PI), Khalid Mosalam, Julio Ramirez, Judy Steele, Jon Stewart

Project background California, 1994Turkey, 2003 “50% of the casualties are coming from 5% of the buildings.” Kircher et al., “Estimated Losses due to a Repeat of the 1906 San Francisco Earthquake, Earthquake Spectra, 2006.

Project thesis Available guidelines are too conservative –most buildings are found inadequate –retrofit costs are high This “always bad” message –is not credible –is impeding action Improved procedures –can reduce the problem –can make retrofit programs feasible What we learn, both technical and societal, can be translated to other building types and localities.

Research program overview Inventory one or two major cities Test critical components to collapse Investigate simple retrofit methods Systems studies, including soil- foundation-structure interaction Improved computer simulation Regional simulation Craft and evaluate appropriate policies –Identify different classes of the problem Structural configuration Occupancy Economic conditions –Identify feasible mechanisms –Model risk reduction impacts –Evaluate economic impacts

Collaborations with existing organizations ASCE Standards Committees American Concrete Institute Applied Technology Council EERI Concrete Coalition